5,462 research outputs found
Use of cumulants to quantify uncertainties in the HBT measurements of the homogeneity regions
Let us denote p(x|K) the space density of the points where identical
particles of some kind, e.g. pi+ mesons, with momentum K are produced. When
using the HBT method to determine p(x|K) one encounters ambiguities. We show
that these ambiguities do not affect the even cumulants of the distribution
p(x|K). In particular, the HBT radii of the homogeneity regions, which are
given by the second order cumulants, and the distribution of distances between
the pairs of production points for particles with momentum K can be reliably
measured. The odd cumulants are ambiguous. The are, however, correlated. In
particular, when the average position (K) is known as a function of K there
is no further ambiguity.Comment: LateX, 10 pages, no figure
Determinants of Quality Management Efficiency in Polish Food Processing Industry
A questionnaire method has been used to collect the empirical data on the food processing enterprises. Data were collected for 36 out of 68 enterprises having ISO 9001 / 2 (April 2000). Value chain as a modelling power of competitive advantage, determinants of quality management system efficiency, participation of knowledge and skills in formation of firm competence were discussed.Agribusiness,
Food Safety. Commodity Science Point of View
The paper addresses "food safety" and 'food quality' from the position of commodity and food science rather than economy. The various descriptions of both terms in literature are reviewed in connection with customer/supplier ability to evaluate food safety and quality by examination of various characteristics. Food safety has been described as opposite to food risk. Differences in perception of food risk by customer, producer/supplier and official agencies are discussed in this paper. The objective safety (and quality) of food can be evaluated using three categories of food risk (biological, chemical and physical) measured on a seven step intensity scale by producers and official agencies but not by customers. This leads to formulating food safety policy which has been described as a set of voluntary, obligatory and supplementary systems under inspection of official bodies. The efficiency of this formulation has been examined and described for Wielkopolska region of Poland. The results indicate sufficient analytical performance of laboratories in industry and some gaps in co-operation with official food safety control institutions.food safety, food quality, risk, Food Consumption/Nutrition/Food Safety, Q13, Q18, M31,
Intracellular zinc depletion induces caspase activation and p21Waf1/Cip1 cleavage in human epithelial cell lines
To better understand the mechanisms by which zinc deficiency induces epithelial cell death, studies were done of the effects of intracellular zinc depletion induced by the zinc chelator TPEN on apoptosis-related events in human malignant epithelial cell lines LIM1215 (colonic), NCI-H292 (bronchial), and A549 (alveolar type II). In TPEN-treated cells, depletion of zinc was followed by activation of caspase-3 (as demonstrated by enzymatic assay and Western blotting), DNA fragmentation, and morphologic changes. Increase in caspase-3 activity began 1–2 h after addition of TPEN, suggesting that zinc may suppress a step just before the activation of this caspase. Caspase-6, a mediator of caspase-3 processing, also increased, but later than caspase-3. Effects of TPEN on apoptosis were completely prevented by exogenous ZnSO4 and partially prevented by peptide caspase inhibitors. A critical substrate of caspase-3 may be the cell cycle regulator p21Waf1/Cip1, which was rapidly cleaved in TPEN-treated cells to a 15-kDa fragment before further degradation.F. Chai, A. Q. Truong-Tran, A. Evdokiou, G. P. Young and P. D. Zalewsk
Electronic health records to facilitate clinical research
Electronic health records (EHRs) provide opportunities to enhance patient care, embed performance measures in clinical practice, and facilitate clinical research. Concerns have been raised about the increasing recruitment challenges in trials, burdensome and obtrusive data collection, and uncertain generalizability of the results. Leveraging electronic health records to counterbalance these trends is an area of intense interest. The initial applications of electronic health records, as the primary data source is envisioned for observational studies, embedded pragmatic or post-marketing registry-based randomized studies, or comparative effectiveness studies. Advancing this approach to randomized clinical trials, electronic health records may potentially be used to assess study feasibility, to facilitate patient recruitment, and streamline data collection at baseline and follow-up. Ensuring data security and privacy, overcoming the challenges associated with linking diverse systems and maintaining infrastructure for repeat use of high quality data, are some of the challenges associated with using electronic health records in clinical research. Collaboration between academia, industry, regulatory bodies, policy makers, patients, and electronic health record vendors is critical for the greater use of electronic health records in clinical research. This manuscript identifies the key steps required to advance the role of electronic health records in cardiovascular clinical research
Some forgotten features of the Bose Einstein Correlations
Notwithstanding the visible maturity of the subject of Bose-Einstein
Correlations (BEC), as witnessed nowadays, we would like to bring to ones
attention two points, which apparently did not received attention they deserve:
the problem of the choice of the form of correlation function when
effects of partial coherence of the hadronizing source are to be included and
the feasibility to model effects of Bose-Einstein statistics, in particular the
BEC, by direct numerical simulations.Comment: Talk delivered by G.Wilk at the International Workshop {\it
Relativistic Nuclear Physics: from Nuclotron to LHC energies}, Kiev, June
18-22, 2007, Ukraine; misprints correcte
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